wined3d: Add SURFACE_BUSY support to *_Blt.

dlls/wined3d/surface.c

@@ -3436,6 +3436,12 @@ static HRESULT WINAPI IWineD3DSurfaceImpl_Blt(IWineD3DSurface *iface, RECT *Dest
     TRACE("(%p)->(%p,%p,%p,%x,%p)\n", This, DestRect, SrcSurface, SrcRect, Flags, DDBltFx);
     TRACE("(%p): Usage is %s\n", This, debug_d3dusage(This->resource.usage));
 
+    if ( (This->Flags & SFLAG_LOCKED) || ((Src != NULL) && (Src->Flags & SFLAG_LOCKED)))
+    {
+        WARN(" Surface is busy, returning DDERR_SURFACEBUSY\n");
+        return WINEDDERR_SURFACEBUSY;
+    }
+
     /* Accessing the depth stencil is supposed to fail between a BeginScene and EndScene pair,
      * except depth blits, which seem to work
      */